Bending machines with reversible motor drive



BENDING MACHINES WITH REVERSIBLE MOTOR DRIVE Filed March 30, 1956 May 5, 1959 R. M. SHAW, JR

5 Sheets-Sheet l INVENTOR. M5

12 Z510 JP.

ATTORNEYS May 5, 1959 R. M. SHAW, JR 2,834,987

BENDING MACHINES WITH REVERSIBLE MOTOR DRIVE Filed March 30, 1956 3 Sheets-Sheet 2 A TTORNE Y5 May 5, 1959 R. M. SHAW, JR Y 2,334,937

BENDING MACHINES WITH REVERSIBLE MOTOR DRIVE Filed March so, 1956 s Sheets-Sheet 3 FIG; 6K 25 IN VEN TOR.

A TTORNEYS BENDING MACHINES WITH REVERSIBLE MOTOR DRIVE Application March 30, 1956, Serial No. 575,233

1 Claim. (Cl. 153-45) This invention relates to bending machines. More specifically, it is concerned with machines for angularly bending rods, bars, tubes and the like of metal or other flexible materials.

The'chief aim of my invention is to provide a simple, inexpensive and reliable machine by which multiple bending operations of the kind referred to can be quickly and economically accomplished at one time with assurance of accurate duplication in the work pieces successively produced in the machine.

In connection with a bending machine having the above attributes, it is a further aim to provide adjustable facilities whereby the machine can be adapted for the bending of the work pieces to various angles and configurations.

Other objects and attendant advantages will appear from the following detailed description of the attached drawings, wherein:

Fig. 1 is a view in top plan of a bending machine conveniently embodying my invention.

Fig. 2 is a view in vertical section taken as indicated by the angled arrows Il--II in Fig. 1.

Fig. 3 is a fragmentary detail sectional view taken as indicated by the angled arrows I1I-III in Fig. l and drawn to a larger scale.

Fig. 4 is a view in top plan similar to Fig. 1 and showing how the bending is efiected in the machine;

Fig. 5 is a perspective view illustrative of a type of the bending which can be done in the machine.

As herein illustrated, my improved bending machine comprises a pair of table-like units 1 and 2 which are reverse duplicates of each other both as regards their design and appointments and which are adjustable toward or away from each other along a pair of fixed track rails 3. Each unit has a recessed top 4 which is semicircular in configuration supported at waist height by side and end legs 5 and 6 from a base plate 7 bridged crosswise over the rails 3. Clamps 8, underreaching the upper flanges of the rails 3 and adapted to be tightened by cap screws 9, serve a means for holding the units 1 and 2 against accidentally shifting after adjustment. Bolted to the underside of the table top 4 of each unit 1, 2 is a reversible electric motor 10 with an in built speed reducer 11 whereof the output shaft 12 extends up through the table top and is provided at its protruding end with an afiixed spur pinion 13. Free to rotate about an upstanding stud 14 fixed in the axis of each table top 4 is a spur pinion 15 which is arranged to be driven, through an idler spur wheel 16, from the pinion 13. Splined as at 17 (Fig. 3) to an upward hub projection of each pinion 15 is an arm 18 which has a longitudinal slot 19 for guidance 0'? a slide 20 having a pair of spaced upstanding posts 21 over which a round taper-end swaging block 22 is engaged. As shown, the slide is adjustable along the slot of the arm 18 by means of a screw spindle 23. Impaled upon the upper end of each stud 14 about the spur pinion 15 and fixed against rotation by a removable key 25, is a circular die element 26 having United States Patent 0 a circumferential groove 27 which, in the present instance, is rounded in cross section.

It is to be understood that the motors 10 respectively associated with the units 1 and 2 are connected for operation in'unison. Forward reverse and stop switches 30, 31 and 32 (Fig. l) are provided for manual control of the motors 10; and attached to the edge of the table top 4 of each unit are a circuit reversing stop switch 33, a circuit reversing switch 34 and a stop switch 35, the latter two switches being circumferentially adjustable about the table top relative to the switch 33. In practice, the switches 3335 respectively of the two units are so arranged in a suitable wiring circuit or circuits (not illustrated) as to function in the manner presently explained, the switches 3335 being individually tripped through engagement of their actuating levers by pendent lugs 36 on the arms 18.

- Operation With the arms 18 in the normal or parallel position of Fig. l, a cylindrical rod or tube 37 to be bent is laid transversely of the arms 18 tangentially within the grooves 27 ofthe die elements 26 and between the latter and the cooperative swaging elements 22. All being now in readiness, the forward push-button 30 is pressed to start the motors 11 whereupon, through the gears 13, 16 and 15 the arms 18 are swung contrariwise about the fulcrum studs 14 as indicated by the arrows in Fig. 4, and by action of the swaging elements 22, the end portions of the rod 37 are progressively bent about the die elements 26. This action continues until the arms 18 reach the broken line positions in Fig. 4, when the switches 34 are tripped by the lugs 36 on said arms to reverse the motors 10. When, in their return movement, the arms 18 reach the aligned relationship in which they are shown in full lines in Fig. 4, the switches 35 are automatically tripped by the lugs 36 on said arms to stop the motors. The rod or tube 36, now bent to U configuration, is then removed from the machine, and the motors 10 thereupon restarted in reverse by pushing the reverse button 31. Finally, upon return of the arms 18 to the normal position in Fig. 1, the switches 33 are automatically actuated by the lugs 36 on said arms and the machine thus made ready for another bending operation. In the bending, the arms 18 are turned somewhat in excess of a quadrant as above described to compensate for the inherent springiness of the rod or tube. Accordingly, upon relief of the pressure upon the legs of the now U-bent work piece, the legs of the U will assume a parallel relationship as shown in Fig. 4. Obviously, by adjusting the switches about the table tops 4, the end portions of rods or tubes can be bent to other complemental or difierent angles in either acute or obtuse relation.

For the bending of U shaped pieces having cross bars of a length less or greater than shown the spacing of the die elements 26 is increased or decreased by adjusting the unit 2, upon easement of the clamps 8 along the rails 3, either toward or away from the units 1 and securing it in the new position of adjustment by retightening said clamps.

For the bending of rods or tubes of polygonal or other cross sections, die elements with correspondingly configured grooves may be substituted for the die elements 26 herein shown by way of example. Moreover, die ele ments diifering in diameter may be used on the respective units 1 and 2 and the swaging elements 22 adjusted along the arms 18 to suit. Also additional die elements may be applied to the studs 14 over the die elements 26 and additional swaging elements superimposed upon the swaging element 22 as instanced in broken lines in Fig. 2, the machine being thereby adapted for bending several rods or tubes concurrently. It will thus be seen that,

with my improved machine, it is possible to accurately bend rods, tubes and the like to various shapes and configurations as may be desired or required to meet exacting specifications.

While in accordance with the provisions of the statutes, I have illustrated and described the best forms of embodiment of my invention now known to me it will be apparcut to those skilled in the art that changes may be made in the form of the apparatus described without departing from the spirit and scope of the invention, as set forth in the appended claim, and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

Having thus described my invention, I claim:

In a bending machine a pair of coplanar semicircular supports with their diametral edges confronting each other; a transverse guideway to which the supports are constrained .for adjustment toward and away from each other in a direction perpendicular to said diametral edges; fixed short vertical studs upstanding from the respective supports; circular die elements aflixed to the tops of the respective studs; arms respectively fulcrumed on the studs; spur pinions affixed to the arms and rotatable about the studs; wiper elements on the arms between which and the die elements a rod or the like to be bent is placed when said arms are parallel to each other and to the diametral edges of the supports; separate electric motors on the respective supports; spur transmission gears between shafts of the respective motors and the aforesaid pinions where- 4 by, upon starting the motors, the arms are moved contrariwise to cause the wiping elements to bend the rod about the respective die elements; limit switches adjustable to different extents about the curved edges of the respective supports and adapted to be engaged by the respective arms for opening the circuits to the individual motors when opposite end portions of the rod have been bent to the desired extents about the respective die elements; reversing switches independently adjustable about said curved edges and adapted to be engaged by the respective arms for reversing said motors after the limit switches have been actuated; and additional limit switches at the curved edges of the respective supports adapted to be actuated by the arms to stop the motors upon return of the arms into parallel relation in readiness for, another bending operation.

References Cited in the file of this patent UNITED STATES PATENTS 957,199 Gail May 10, 1910 957,200 Gail May 10, 1910 998,394 Richards July 18, 1911 2,266,912 Shaw Dec. 23, 1941 2,413,524 Shaw Dec. 31, 1946 2,453,868 Shaw Nov. 16, 194: 2,661,788 Esslinger Dec. 8, 1953 FOREIGN PATENTS 558,203 Great Britain Dec. 24, 1943 

